Nova Patents
US7855151B2

Formation of a slot in a silicon substrate

Summary by NHIP

Slot formation in silicon substrate

The method forms a slot through a silicon substrate using sequential laser patterning, dry etching, and wet etching. Distinctive steps include laser patterning a trench leaving 60 to 75 microns of silicon, followed by dry etching to approximately reach the second side before a wet etch completes the slot.

Claim Score by NHIP

Read claim 1, the broadest

Abstract

A slot is formed that reaches through a first side of a silicon substrate to a second side of the silicon substrate. A trench is laser patterned. The trench has a mouth at the first side of the silicon substrate. The trench does not reach the second side of the silicon substrate. The trench is dry etched until a depth of at least a portion of the trench is extended approximately to the second side of the silicon substrate (12). A wet etch is performed to complete formation of the slot. The wet etch etches silicon from all surfaces of the trench.

US7855151B2, drawing sheet 1
Sheet 1 of 5

Term

Projected expiry 22 May 2029.

  1. Priority and filed
  2. Granted
  3. Today
  4. Projected expiry

12 claims: 2 independent, 10 dependent

  1. 1
    Broadest claimClaim Score 63, broad(NHIP)A method for forming a slot that reaches through a first side of a silicon substrate to a second side of the silicon substrate, the method comprising:placing wet etch masking material over the first side of the silicon substrate;removing the wet etch masking material to expose a trench area;placing dry etch masking material over the exposed trench area and the wet etch masking material;laser patterning a trench, the trench not reaching to the second side of the silicon substrate;dry etching the trench until a depth of the trench is extended approximately to the second side of the silicon substrate;and, performing a wet etch to complete formation of the slot, the wet etch removing the dry etch masking material and etching silicon from all surfaces of the trench.
  2. 7
    A method for forming a slot that reaches through a first side of a silicon substrate to thin films located on a second side of the silicon substrate, the method comprising:placing wet etch masking material over the first side of the silicon substrate;removing the wet etch masking material to expose a trench area;placing dry etch masking material over the exposed trench area and the wet etch masking material;laser patterning a trench, the trench having a mouth at the first side of the silicon substrate and the trench not reaching the thin films;dry etching the trench until a depth of at least a portion of the trench is extended approximately to the second side of the silicon substrate;and, performing a wet etch to complete formation of the slot, the wet etch etching silicon from all surfaces of the trench.
Independent claims2